Rotary brush



Sept. 9, 1952 R. o. PETERSON 2,609,559

ROTARY BRUSH Filed March 5, 1947 4sheetssheet 1 uJbUHlm N INVEN TOR.

/ RUBEN O. PETeRo/v Sept 9, 1952- R. o. PETERSN 2,609,559

I ROTARY BRUSH Filed March 5, 1947 4 sheets-sheet 2 JNVENToR. nuf/v o. Pamesa/v MLQU, Y

ATTO/Neva Sept. 9, 1952 R. o. PETERSON ROTARY BRUSH 4 Sheets-Sheet 3 Filed March 5, 1947 JNVENTOR. RUBEN. o. PETERSON ATTONEY.

Sept. 9, 1952 R. o. PETERSON 2,609,559

ROTARY BRUSH Filed March 5, 194'? 4 Sheets-Sheet 4 s, s 38 54 E 55 5 3 5 5 if-es 3 4 4 5o @Kfm-Lauf 5| 4 4o/ 4l I 57 lfm 3K9. /5 JCQ. /4 5,19. /5

INVENTOR.

RUBEN 0. PET E E5 ON BY 06M? MJ ATTO lame 5 Patented Sept. 9,

UNITED STATES PATENT l'oF-El,elf;

ROTARY BRUSH Ruben O. Peterson, UniversityHeights, Ohio, as- Manufacturing Company, Cleveland, corporation of Ohio ApplicationMarch `5, 1947, .Serial N o. :3732,d45

Thisinventon relates, as indicated, to rotary brushes and more particularly to rotary brushes of the type which are adapted to be vmounted on power driven mandrels and operated at high rates .0f speed.

, Peterson Patent No. `2,303,386 discloses an improved form ofbrursh strip whichl is adapted to continuous production and winch may be circular-ized into any desired number of convolutions. While such strip is .constructed ina manner firmly to Vsecure the brush lmaterial therein nevertheless Various problems .are presented When such strip is to be formed into rotary brushes and mounted on a mandrel `for .high .Speed operation. :When only one ,convolution is employed, thereby obtaining an annular section, it has been common practice to vWeld the .channel back ends togetherand either to twist the retaining wire together `or to bend'the endsthereof into notches in the side Walls of the channel. V.'Ihe Welding .Operation is slow and .expensive and is likely to injure the Ybrush material. .The bursting strength of the brush is not as high as desired.

Another method, long in use, has been to mount .a single convolution, with slightlyioverlapping ends', `o n a mandrel or .boss'lbetween two dished clamping plates, the inturned' annular anges of which overlie the outeredges of the channelform brush iback. Such' method, while greatly increasingl .the Vbursting strength, is `ordinarily not suitable when a plurality rof such annular sections are to be .assembled in close side by side relation toform a larger cylindrical or roller brush since .the brush material of 'adjacent sections willtbe kept from close lateral engagement and .the brush will present a nonuniform surface. Furthermore, this method is not entirely suitable even in the caseoi 'a single convolution for the reason that the pressure required to make the inturned peripheral edges of the iiange portions .effective for holding the brush .part against forces which act-on'it when rotated at high speeds excessively concentrates Working stresses in the brush material at the point of Contact with said inturned edges. "Such concentrated working stresses cause' excessive hreakageof the brush material in use, especially when such material is flexed in a direction .nor-

mal `to the pressure. When this method is` applied v.to several convolutio-ns `forming a unit brush the percentage of breakage of .brush materiafis'reduced by the increase of total brush material, 'but the amount of breakage lcaused adjacent tothe inturned edges .isneT/tertheless xgssive'h se einige. (cin-1s?) v As indicated, generally similar problems Aare presented when a plurality of convolutions are employed to form la helically Wound brush. Here, :of course, it is impossible t0 iustapose the ends of the brush, back for welding tosetheraed other means must be found for holding `the conf volutions tightly seated on the mandrel. The ends of the convolutions must not only be prevented 4from radially outward movement must also be heldagainst circumferentia ping or unwinding which would cause nthe Y, mediate convolutiens to come 10.05 :and :huiseoutwardly. Various types of end `plates 'haye been simplex/,ed .te which the ends -ofi thestrip could be secured but these are fussy t'o-use .and unsuitable where .a `niunber of* hel-wally Weimd seetionsare to -be employed in asseciaton. as they do not permit close enough assembling ofqthe sections. l

While a brush strip vconstructed in :accordance with my aforesaid prior patent 'sreatly strengthened by means of `the inturned teeth which hold the brush material retaining member in place it is nevertheless obvious that the bursting strength vof a circuilarized section thus'forrned can be no greater than that of the channelfo'rm back.

It is, therefore, a lprimaryobject of my invention to provide means for vmounting:rotary:brnsh elements upon amandrel in a manner adapted greatly to `increase the bursting Vstrength .of the brush.

'A further object `is to provide meansdor` mounting a crculariaed `brush elementupon la mandrel :eiective to prevent *'.un'winiing thereof andto maintain such element tightly `seated'on the mandrel. r

A ,further vobject .is to provide means torrjoining together adjacent .brush sectionsuponta manjdrel to forma unitary brush. l

Another object is to provide a `rotary .brush having a .stepped .or tapered face in Which-.the bristle length will nevertheless .belsubstantially uniform `Within vreasonable limitations,`r'thereby affording uniform brushing .cha'racteristics.

Still another object is'to provide'a circularimd channelform brush strip mounted onA a core porftion in such manner 'as to iprovideatunitary rotary brush of high bursting strengthand long life. A Y

`Other objects of .this invention will appearzas the description proceeds. l

To the accomplishment of the foregoing and related ends, said invention thencornprises ,the

ferilli@ hereinafter .fully described and particu:

larly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In saidv annexed drawings:

Fig. 1-is a sectional view axially of a rotary brush constructed in accordance with my invention;

Fig. 2 is an end view of such brush showing the end retaining flange;

Fig. 3 is a View similar to Fig. 1 but showing another means of locking the end flange in place;

Fig. 4 is an end View of the construction of Fig. 3;

Fig. 5 is a sectional view axially of a composite tapered brush in which the different brush elements have been assembled in accordance with my invention;

Fig. 6 is a sectional view along the line 6 6 on Fig. 5;

y Fig. 7 is a view of a rotary brush assembly with the brush material cut away down to the channelform' brush back to show the disposition of the retaining members;

Fig. 8 is a perspective view of the end retaining member of Fig. 7

Fig. 9 is a perspective View of the brush unit interconnecting member of Fig. 7;

Fig. 10 is a fragmentary elevational View of a retaining member provided with an additional outer row of teeth;

, Fig. 11 is a sectional View taken along the line I l-i I on Fig. 10;

l Fig. 12 is a fragmentary end elevational view of a unitary rotary brush assembly formed in accordance with my invention;

Fig. 13 is a sectional view of such brush taken along the line l3-l3 on Fig. 12;

UFig. 14 is a similar sectional view but showing another embodiment wherein a larger number of turns of brush strip are mounted on a core portion; and

. Fig. 15 is a similar sectional View of an embodiment in which but a single turn is thus mounted.

Referring now more particularly to such drawings, and especially Figs. 1 and 2 thereof, the brush of this invention may comprise one or more turns of a circularized brush strip mounted upon a mandrel l. As illustrated, such brush strip may be formed in the manner taught in my Patent No. 2,303,386 comprising radially extending brush material 2 held within a channelform back 3 by means of a retaining member such as wire 4 which is itself firmly held Within such channel by means of overlying teeth 5 punched in from the respective sides of such channelform back. Fig. l shows a plurality of such brush elements assembled upon the mandrel, each element comprising a plurality of helical turns of such brush strip. Shown interposed between two such elements is a flat annular-retaining ring 6 seated upon the mandrel and provided with a plurality of circularly disposed teeth 1 projecting to each side in an axial direction. Such teeth are provided with inner inclined edges and are radially spaced to indent and bear against the respective peripheral edges of the endmost turns of such helically wound channelform brush back. It will thus be seen that, when such circularized brush elements are assembled with the above-described retaining member therebetween and laterally compressed, the inclined edges ofthe teeth of such retaining member will cam down the respective adjacent edges of the cha1i nelform brush back, thereby firmly seating such brush backs upon the mandrel and upon being thus tightly compressed, such teeth will indent or notch the edges of the brush back thereby locking the adjacent helically wound brush elements together into onepunit.

As also shown-in Fig. 1, such retaining member may desirably be secured against rotation relative to the mandrel as by means of an inwardly projecting tab 8 welded thereto and adapted to extend into a keyway 9 in such mandrel. In this manner a cylindrical rotary brush of considerableV length may be assembled of a plurality of helically wound brush elements, such elements not only being interlocked and firmly seated upon the mandrel through action of such retaining member but also secured against possibility of slipping and rotation relative to the mandrel.

The outer ends of the brush may similarly be secured by means of an annular retaining member l0 provided with a plurality of circularly disposed teeth l l projecting to one side only and similarly overlying and indenting the outer peripheral edge of the channelform back. Such endmost retaining member will also desirably be provided with a locking tab or key l2 fitting in keyway 9. A nut I3 is adapted to be screwed on to the threaded end of the mandrel to bear against the endmost retaining member I0 and hold the brush elements in assembled relation.

Referring now to Figs. 3 and 4 an alternative means for securing the end retaining member is there illustrated. In this example such end retaining member I4 is provided with an axially extending fiange l5 at its inner periphery adapted to be seated upon the mandrel i. Such flange is periodically expanded as at i6 to permit a hardened pin Il provided with a self-tapping thread to be driven into the opening formed thereby thus firmly securing such retaining memberinplace.

As shown in both Figs. 1 and 3 such endmost retaining member will desirably have an annular inwardly directed bulged portion I8 adjacent its outer periphery adapted to compress the brush material of the endmost turn of the circularized brush back since, of course, such brush material is not supported to this side by the material of an adjoining turn.

The retaining member of this invention may not only be employed to interlock adjoining brush elements of the same diameter, as shown in Fig. 1, but may also` be employed where it is desired to assemble brush elements of Varying diameters. It is ordinarily not desirable to form a cylindrical brush having a longitudinally stepped face by employing a plurality of turns of a brush strip having brush material of a uniform length and trimming down desired portions of the brush material to obtain a brush of varying diameter. Due to the difference in length of the brush material extending from the brush back at different points along the length of such a brush very diierent brushing characteristics would be obtained with resultant non-uniform effect upon the work being brushed.

As shown in Figs. 5 and 6, by employing a mandrel comprising cylindrical portions of different diameters l9 and 20 this difficulty may be overcome. A brush having a stepped face, as indicated in dot-and-dash line on such Fig. 5, will thus result. This brush may then be trimmed to the tapered contour shown Without any very great V:variation in bristle .length *resulting 'from 4fone VTend lto-'the other ;of Ithegbrush. In order :to lock two such yadjoining .brush elements-,together anu-annular :retaining ring 2| is providedseated on :the-smaller diameter portion of the mandrel `and provided with circularly `arranged teeth pro- 'J'ecting axially in each direction, the teeth 22 vbeing less `radially outwardly spaced thanfteeth 23 in order to indentand bear againstthe outer peripheral vedge of the channelform brush back ym'ounted'on.portion 20 whilev teeth 23 areiadapted -to indent and bearagainstthe .edge of Athe vbrush lback mounted upon fthe 'zlarger mandrel portion'IS.

While itis common practice to laterally com.-

pre`ssa1helically `Wounclirotary i brush element to cause such 'element/to conform to fendy flanges ynormal to theaxis of thelmandreLit is advan- :tageous for certain purposes, :as Well as more convenient, to permit such helically 'woundfele- 'ments 4to retain vtheir. normal oiset Arelationship :when'mountedzupon'the mandrel. .For'this pur- `pose a particular modication Soi thevabove-de- -scribed -annular retaining .member is illustrated yin Figs. 7-9 inclusive. A hat annular retaining l ring 24 (see Fig. 8) is' seated on 'the mandrel I 4a't--one end of the helically wound brush element provided with va plurality of circularly arranged -teeth :25 adapted to lIindent and bear against a peripheral edge of the brush back`,-'portion 26 of such Yretaining member being axially oiset to :conform to the 'end 21 of :the helically Wound 'brush element. End Anut I 3 is adapted to .hold Asuch end retaining member firmly in lplace and a fkey "28 may desirably be provided on such retainof the brush back being provided whereby-such "retaining member may conform to the 'opposed ends'33 and`34 ofsuch brush-backs.

"nrotarybrushes ofthe 'general-type' described -ab'ove it"hasbeen found that the Vbrush-material fgener'ally `rst `fails-'and-breaks at the pointwhere TNthe -same leaves 'the channelform back. At Ithis point'the material is -tightlylcompressed and in ordinary use itis at this pointwhere most-of the 'flexure of the individual bristles'takes place. In order to extend the length of that Yportion ofthe brush'bristle at which such .Flexure takes place, and thereby increasethe life lof the brush, it has lbeen y'found :desirable to provide an additional vlouter'-radiallyspac'e'd row'of teeth 'on my new're- 'ftalningmembers which have theie'iifect, particu- .flarly in cooperationwith the inner row of teeth Iivvhich `bear upon VKthe edge ofthe channelform brush back, of 1causing suchiiexure to be ldisitrlbuted along thatportion-of thebristle length .flying between-suchtwolrows ofteeth. These additional teeth .may bef-employed onfboth my --end retaining members Aand my intennediateretaining-members. v

Flgsmlgfand llashow fragmentary detail fviews lofseuch.an;intermediate'memberias provided with 71-,

an :inn-er row of teeth 36 rand .aan :outer-.row pf teeth-3l,l .it kbeing `'noted that such iteeth-zare farranged vin radially disposed `pairs projectingfin the same directions. The inner row of teethr is, ofcourse, adapted to indent .and bear fagainst the vedge'of the fchannelform brushA back. f,

`While the retainingmembers of my invention areI yparticularly valuable for use inv conjunction with one or more v'circularized turns of -a-brush strip the :ends vof -whichfare ,not joined-to -fiform a continuous annulus, such:retainingfmembersfmay' .nevertheless .be employed to fgreatvadvantage with ordinary .rotary brushsections `having continuous annular fbrush backs; :In jsuch. case-the teethzof the retaining member whichf-bearrupon the y:router .periphery of rvthe brush backV serve Igreatly.tofincrease the rburstingrstrength ofgsuch brush' :and an outer row ofteeth such fasf.3'I will .similarly increase the life of the `brushmaterial by -causingthe exure -of the-same' to be more :generally distributed. The -form of retaining member provided `with' `teeth vextending to feither side ithereof, as shown in Fig. .1 fprvexamplamay likewise be;employedgto reinforce andfinterlock such adjoining-annular sections. n

The brushmaterialf-rnay'befofl anyof theatypes einployedin rotary brushes including Tampico fiber, wire, cord, and strands of syntheticiplastic. :As'shown in Figs. 12 to l5;inclusive,gthe prinv.cible i .0f my` invention z may .he -femployed not only fn Amounting rotary ybrush elements directly :on a mandrel but also in embodiments whereingsuch elements are mounted -pon separate cylindrical v'corev portions which :in `turn may be slid-,upon .amandrel or Ysupported by conventional-adapters. yIn the form illustrated-,in Figs. 12j-and -i113 fthe .annular retainllgfmembers bv38 and 39 are :provvvided with` opposed-cylindrical core portions 4U IandgliI/on whichthe turns ofbrush strip 3;-are seated- Radiallv inwardly directed anges 4.2 Aand 43 are Yjoined byrupset portionsfddnwhich Vserve to-rivet the two togetherholding them in close compressive engagement with the circularized brush element. Teeth =45 andfll serve fin L Ythe'fsame manner asteeth I I `jinftheulig. lem- ;bodiment tov indent rand; bear vagainst the edge-.of

thepchannelform back 3.

Fig. 14 shows two end retaining membersz .and 48-generallysimilar to zmemberlgllofiFig. 1 :ibut mountedon a lengthof tubing 4'9fand held inplace by upset .ends Euland 15|. V'Il'ieQl-ielical convolutions/of brush strip vretained therebetween injcompressed relationship .are .-held infgplace by lteeth '52 and 53 arranged; in jlikemanner ,tothe teethof .theFig l embodiment. Fig. 1'5 fshvows a *single convolution clamped betweentwo retain- .ing members 54 and 55,each of fwhich will desir- -rably be `provided with teeth .fsuch las @56. .The ginnergperipheral -iiange 57 of memberad is upset vto lock the twoimembers .together to iform; a zuniitary* rotary .brush fwherein the. channelform back 3 of the brush istripftisnseated-on opposed cylindrical core portions of .suchimembers liIt 'will :be .apparent fromthe foregoingthat rotary. brushzelements may be'mounted -inlaccordiance :with my 'inventioneither directly-jupon a `solid for :tubular mandrel oruponV separate core -portions formed, for example, k.by yaxial -annular extensions ofthe retaining members. Themanvdrel for other core V"will ordinarily be fcylindrical in form although it vmay-be of other crossfsec- When van annular rotary brush `element comprising; one or more turns` of brush strip iisemountedvasitaught hereinand yaui-numberrare yassembleiifrto provide a 7 composite brush it is readily apparent that should one portion of the brush be damaged'it may be replaced Without having to discard the entire brush.

'Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

'1. In combination, a mandrel; a rotary brush element seated on said mandrel, said element comprising a plurality of helical turns of a channelform brush back having teeth punched inwardly from the sides thereof, a retaining member disposed longitudinally Within said channelform back and held in place: beneath said teeth, `and brush material held in said channelform back by said retaining member; annular retain- `ing members seated on said mandrel to either side of said helically Wound brush element and provided With a plurality of circularly disposed teeth projecting in an axial direction adapted to indent and bear against the respective peripheral edges of the endmost turns of said helically Wound channelform brush back; and a nut threaded onithe end of said mandrel operative, upon being tightened, to bear against one of said toothed annular retaining members to force such teeth into such engagement with the edge of said brush back.

- '2. In combination, a cylindrical core; a rotary brush element seated on said core, said element comprising a plurality of helical turns of a channelform brush back having teeth punched in- Wardly from the sides thereof, a retaining member disposed longitudinally within said channelform back and held in place beneath said teeth, and brush material held in said channelform back by said retaining member; and annular retaining members 'seated on said core to either side of said helically wound brush element and provided with a plurality of circularly disposed teeth projecting in an axial direction indenting and bearing against the respective peripheral edges of the endmost-turns of said helically wound channelform brush back.

`3. In combination, a cylindrical core; an annular rotary brush element seated on said core, said element comprising a circularized channelform back having teeth punched inwardly from the sides thereof, a retaining member disposed longitudinally within said channelform back and held in place beneath said teeth, and brush material held in said channelform back by said retaining member; and annular retaining members seated on said core to either side of said' element and provided with a plurality of circularly disposed teeth projecting in an axial direction and indenting and bearing against the respective peripheral edgesof said channelform back. A A

4. In combination, a cylindrical core, a rotary brush element seated on said core, said element comprising a plurality of helical turns of a circularized channelform brush back having radially extending brush material secured therein, and annular retaining members seated on said core to either side of said helically Wound brush element and provided with aplurality of circularly disposed teeth projecting in an axial direction indenting and bearing against the respective peripheral edges of the endmost turns of said helically wound channelform brush back. l5.In combination, a 4cylindrical, core,Y arotary. brush element seated on said core, ,said element comprising a plurality of helical. turns of a circularized channelform brush back having radially extending brush material secured therein, and an annular retaining memberseated onsaid core and provided with a plurality of circularly disposed teeth projecting in an axial direction indenting and bearing against a peripheral edge of such brush back.

6. In combination, a cylindrical core, an, annular rotary brush element seated on said core, said elementI comprising a circularized channelform brush back having radially extending brush material secured therein, and annular retaining members seated on said core to either side of said element and provided with a plurality of circularly disposed teeth projecting in an axial direction indenting and bearing against therespective peripheral edges of such channelform brush back. Y 7. A brush comprising a cylindrical core portion, an annular rotary brush element having a back seated on said core portion, an annular retaining portion provided with a plurality of circularly disposed teeth projecting in an axial direction, and means holding said retaining portion in close relationship with said brush element with such teeth indenting and bearing against the outer periphery of the back of said brush element. i i

3. In combination, a mandrel, an annular rotary brush element having a back seated on said mandrel, and an annular retaining member seated on said mandrel and provided with -agplurality of circularly disposed teeth projecting in an axial direction and indenting and bearing against the outer periphery of such back of said brush element.

9. In combination, a cylindrical core, an annular rotary brush section seated on said core. said section comprising a circularized channelform brush back having radially extending brush material secured therein, and an annular retaining member seated on said core and provided with a plurality of teeth projecting inA an axial direction overlying and bearing against an outer peripheral edge of such channelform back, said teeth being at and thin and lying in radial planes to facilitate penetration of such brush material. l

10. In combination, a core, a rotary brush section seated on said core, said section comprising a circularized channelform back having radially extending brush material secured therein, and an annular retaining member seated on said mandrel provided with a thin flat sheet material tooth projecting in an axial direction and'lying in a radial plane adaptedO to overlie and bear edgewise against an outer peripheral edge of such channelform back.

ll. In combination, a core, a rotary brush section seated on said core, said section comprising a circularized channelformv back having radially extending brush material secured therein, an annular retaining member seated on said core provided with a thin flat tooth projecting in an axial direction andlying in a radial planasaid tooth indenting and bearing against an outer peripheral edge of such. channelform back, and

means adapted to secure said retaining member vagainst rotation relative to said-core.

12. In combination, -a mandrel, a .rotary brush element seated on said mandrel, saidV element comprising a circularized channelform back. having radially extending brush material` secured "tl-'1e1ein-, an annularretaining member. seated on said: mandrel providedy with a plurality of teeth projecting in an axialA direction andindenting and bearing against an 'outer-peripheral edge 'of suchchannelform back, a keyway in said mandrel, and a projection on said' retaining member adapted to t in said keyway to secure said retaining member against rotation relative to said mandrel;

13. In combination, a core, a rotary brush eiement seated on said core, said element comprising a plurality of helical turns of a circulariaed channelform brush back having radially extending brush material secured therein, annular retaining members seated on said core to either sideV of said element provided with a plurality of teeth. projecting in an axial direction and indenting andy bearing against -the respective peripheral edges of the endmost turns of saidV helically wound channelform v brush back, and means adapted to secure said retaining members against rotation relative tov said core.

v14. In combination, a core, two annular rotary brush sections having backs seated. on said core, and an annular retaining member seated on said core between said sections and provided with teeth projecting to each side in an direction and overlyingand bearing against the respective outer peripheries of such backs of said brush sections.

15. In combination, a cylindricalY core, two annular rotary brush sections seated on said core, said sections comprising a circularized channelform back `having radially extending brush materialsecured therein, and an annular retaining member seated on said core between said sections and provided with teeth-projecting to yeach side in an axial direction indenting and bearing against theadjacent peripheral edges of such respective channelform brush backs.

16. In combination,` a cylindrical core, two rotary brush elements seated on said core, said elements comprising a plurality of helical turns ofV a channelform brush back having radially extending brush material secured therein, and an annular retaining member seated on said core between said elements and provided with teeth projecting to each side in an axial direction indenting and bearing against the adjacent peripheral edges of the adjacent endmost turns of said helically wound channelform brush backs.

17. In combination, a core, two rotary brush elements seated on said core, said elements comprising a plurality ofhelical turns of a channelform. brush backl having radially extending brush material secured therein, an annular re-r taining member seated on said core between said elements and providedv with teeth projecting to each side-in an axial direction indenting and bearing-.against the adjacent peripheral edges of the adjacent endmost turns of said helically wound channelform brush backs, and means adapted to secure said retainingA member-against rotation relative to said core. n

- 18. In combination. a core comprising cylindrical portions of diiTerent diameters,` rotary brushelements having backs seated on such portions, and an annular retaining member seated# on. said core between said elements and provided with teeth projecting. to each sidey in an axial direction, the teeth on'each side being respectively radially spacedV t'o overlie and bear against the corresponding adjacentv outer peripheries -of siich` backs of said brush elements. y

19. In combination, a mandrel comprising cylindrical portionsy of di'ierent diameters, 1 rotary brush elements respectively seated-onv such Vportions, saidielements each comprising a plurality of helical turns voi a channelform back having? radially extending brush material secured therein, and an annular retainingring seatedgon said mandrel between said-elements and` proically wound channelform brushbacks.

20. In combination, a mandrel -complkSing two cylindrical portions roi" greater and smaller diameter, rotary brushV elements respectively seated on such portions, said elements each coin,- prising a plurality of helical turns of.v a channelform back having radially extendingwbush material secured therein, such` brush material being trimmed to provide a; continuous'ftap'e from. the greater to the smaller end of said yinfan-1 drel, and an annular retaining` ring seated"v on said mandrel between said elements andprdvided. with teeth projecting to eachside infan axial direction, the teeth on each'side being respectively radially spaced to indent. and bear against the corresponding adjacent peripheral. edges of the adjacent endmost turns '0flsa1dlielrvl ically wound channelform brush backs.

21. As a new article of manufacture, means for securing a rotary brushV element on .-a mandrel comprising a. hat annular ring adaptedto be seated on such mandrel, ak pluralitycf circularly arranged teeth on said ring projectingfto each side in anaxial direction, all said teethon one side being uniformly furtherv radially spaced from the central opening of said ring than :said teeth onv the other side, and aninwardlydirected projection on said ring adapted tozfit inv a key wayin such mandrel.

22. In combination, a core, a rotary brush element seated on said core, said element compris-v ing a plurality of helical turns of a'circularized channelform brush back having radially extending brush material secured thereinp and ai ilat annular retaining ring seated on saidv coreand provided with a plurality-of circularly arranged teeth projecting in an axial direction and indenting and bearing against a peripheral edge of such' brush back, aportion of said ring being-axially offset `to conform to the end of said helically wound brush element. Y i 23. In combination, a core, a rotary brush. element seated on said core, said element comprising a plurality of helical turns of a circularizedchannelform brush back having radially extend-y ing brush material secured therein, anat-annular retaining ring seated on said corefand 4provided with a plurality of circularly arranged' teeth projecting in an axial direction.V and irrdenting and bearing against a peripheral edge ofsuch brush back, a portion of said ring being axially oirset to conform to the'end of saidhelically wound brush element,.and means adapted to prevent rotation of saidretainingring'relativetosaidcore. y -24:..In combination," a core, tworotar'ybrush elements seated on said core`,*said elements com-'-I -prising a plurality of helical turns oi" a'chann'el-"J form brush back having radiauy extending brush materials secured therein, and a at-annul'arfretaining ring seated on said core between said ele` ments and provided With-teeth projecting to each -side in an axial directionv indenting and-bearing against the adjacent peripheral edges ofv the adjacent endmost turns of said helically wound channelform brush backs, said retaining ring being axially offset to conform to the opposed ends of 'said backs.v 1

}25. As a new article of manufacture, means for joining and securing two helically wound rotary brush stripgelements having channelform backs woundfona mandrel comprising a. thin fiat annular ring vadapted to be seated on such mandrel therebetween and provided with a plurality of circularly arranged teeth projecting to each side in an axial direction and spaced from the central opening of said ring, said ring being offset to con- 'form to both of the opposed endmost helical con- `volutions of, 'saidrotary brush elements when interposed therebetween.

2,6."'In combination, a core, anannular rotary brush element having a back seated on said core, andan annular retaining member provided with a pluralityof teeth projecting in anaxial direction/andoverlying andbearing against the outer periphery of such back of said brush element, said retaining memberv being further vprovided withaddi'tional teeth `spaced radially outwardly from 'said firstenamed teeth and` adapted to penetrateythe ybrush material of said element intermediatesaid first-named teeth and the outer brushing surface of said element.

27. In combination, a core, an annular rotary brush element seated on said core, said element comprising a Vcircularized channelform brush backv having radially extending brush material secured therein, andan annular retaining member seated on said core and provided witha plurality of circularly arranged teethY projecting an axial direction indenting and bearing against an ladjacent peripheral edge of said channelform brush backsaid retaining member being further provided Ywith additional teeth spaced outwardly from said first named teeth and adapted to penetrate such brush material intermediate said rst named teeth and the outer brushing surface of said element. f 28. In combination, a core, an annular rotary brush element seated on said core, said element comprising a circularized channelform brush back having radiallyr extending brush material secured therein, and an annular retaining member Aseated on said core and provided with a plurality of circularly arranged teeth projecting in an axial direction and closely overlying an adjacent turn of said brush back, said retaining member being further provided with additional teeth spaced outwardly from said first named teeth and adapted to penetrate such brush material intermediate said first named teeth and the outer brushing surface of said element.

29. In combination, a core, two annular rotary brush elements ,seated on said core, said sections comprising a circularized channel form back having radially extending brush material secured therein, and an annular retaining member seated on said core between said elements and provided'with teethV projecting to each side in an axial direction and indenting and bearing against the adjacent peripheral edges of such respective channelform brush backs, said retaining member being further provided with additional teeth spaced outwardly from said first named teethV and adaptedto penetrate such brush material intermediate said first named teeth and the outer brushing surface ofV said element.

V30. A brushA comprising two supporting members having opposed centrally disposed cylindrical core portions and spaced end retaining portions, an annular rotary brush element seated on such core portions between such end retaining portions, said element comprising a circular channelform back having radially extending brush material retained therein, a plurality of circularly disposed teeth projecting in an axial direction from such end portions and indenting and bearing against outer peripheral edges of such channelform back, and means holding said two supporting members in close compressive relationship to said brush element.

31. A brush comprising two supporting members having opposed centrally disposed cylindrical core portions and spaced end retaining portions, an annular rotary brush element seated on such core portions between such end re-l taining portions, a plurality of circularly disposed teeth projecting in an axial direction from such end portions and indenting and bearing against the outer periphery of the brush back of said element, and mgans holding said two supporting members in close compressive relationship to said brush element.

32. A brush comprising two supporting members having opposed centrally disposed core portions and spaced end retaining portions, an annular rotary brush element having a back seated on such core portions between such end retaining portions, a plurality of circularlydisposed teeth projecting in an axial direction from vat least one such end portion and overlying and bearing against the outer periphery of such back of said brush element, and means holding said two supporting members in close compressive relationship to said brush element.

33. In combination, a cylindrical core, a ro' tary brush element seated on said core, an an-l nular retaining member seated on said core and engaging said brush element, an axially extending flanged portion at the inner periphery of said annular retaining member, and a threaded pin driven between said flanged portion and said core to lock said retaining member in desired position.

34. As a new article of manufacture, means for securing a helically wound rotary brush element on a supporting core, such element comprising an elongated back with a layer of brush material extending therefrom, said securing means comprising a thin flat annular ring having a central aperture therethrough for seating said ring on such core, and a plurality of thin flat teeth on said ring lying in radial planes and extending in a direction parallel to the axis of said ring, said teeth being uniformly spaced radially outwardly from such center aperture with their radially inner edges inclined to overlie and bear against the outer peripheral edge of such helically wound brush back, and said flat annular ring being of helical conformation to nt closely against a corresponding end of such helically' wound brush element on such core.

35. A brush comprising a core portion, an annular rotary brush element having a back seated on said core portion, and a retaining portion provided with a plurality of circularly disposed thin flat teeth projecting in an axial direction which overlie and bear against the outer periphery of such back of said brush element, said thin flat teeth themselves lying in radial planes and therefore presenting their thin dimensionsubstantially parallel to the adjacent strands of brush material'to facilitate penetration therebetween, Y Y

13 14 36. In combination, a core portion, an annular REFERENCES CITED roary brush element havmg a', back seated on The following references are of record in the sald core, and an annular retaining member prome of this'. patent: vided with a plurality of thin at Wheel material teeth projecting in an axial direction and 5 UNITED STATES PATENTS lying in radial planes, said teeth being spaced Number Name Date to overlie and bear edgewise against the outer 1,829,665 Mertes Oct. 27, 1931 periphery of said back of said brush element. 1,869,102 Herold July 26, 1932 2,312,591 Rowland Mar. 2, 1943 RUBEN O- PETERSON- 1o 2,349,643 Wesemeyer May 23, 1944 2,379,205 Wesemeyer June 26, 1945 

